Is there any way to automate windows forms testing?

I am familiar with nunit for unit testing of the business layer however I am looking now to automate the test of the win forms gui layer.

I have seen watin and the watin recorder for automating tests on web application by accessing the controls and automating them. However I am struggling to find a watin equivalent for windows forms (written in c# or vb.net) preferably that is open source.

Does one exist or are all products based on recording mouse and keyboard presses?

Update: I have looked at this blog post on white and it seems the sort of thing I am looking for. The blog post raises some issues but as white is only in version 0.6 these may be resolved. Be interested if others have used white or any others for comparison.